Birmingham, AL Accessory Structures: ADU Rules (2026)
ADU rules in Birmingham, AL, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Code Section
- Ch. 1, Art. III, Sec. 9; Ch. 4, Art. IV, Sec. 2.B
- Max ADU Size
- 800 sq ft or size of primary dwelling, whichever is less
- Units Per Lot
- One accessory structure used as a dwelling
- Access
- From an alley or approved driveway
Summary
Birmingham permits one accessory dwelling unit per lot in specified districts (D-4, D-5, UN, MU and certain commercial zones), capped at 800 square feet or the size of the primary dwelling, whichever is less. Access must be from an alley or approved driveway.
Section 9. Accessory Building Used for Dwelling Purpose. An accessory building may be used for dwelling purposes when all conditions are met, as described in Chapter 4, Article IV, Section 2, Item B. ... B. Dwelling, Accessory. In the D-4, D-5, UN, MU-L, and MU-M, MU-H, MU-D, C-1, and C-2 districts, an accessory dwelling shall be permitted provided the following conditions are met: 1. Only one accessory structure per lot shall be utilized for a dwelling. 2. Access to the accessory dwelling shall be from an alley or an approved driveway. 3. The accessory dwelling shall be accessory to single-family dwelling, Historic Bed and Breakfast or Bed and Breakfast use. ... 32. An Accessory Dwelling Unit may cover more than 30 percent of the required rear yard provided that: a. The Accessory Dwelling Unit is no more than 800 square feet or the size of the primary dwelling, whichever is less. b. The accessory dwelling unit meets the Design Standards, defined elsewhere in this Ordinance.
Full Breakdown
Alabama has no statewide ADU statute; under the municipal zoning authority granted by Title 11, Code of Alabama, ADU rules are set entirely by local ordinance. The City of Birmingham Zoning Ordinance (Ord. No. B. An accessory building may be used for dwelling purposes only when the dwelling conditions are met: only one accessory structure per lot may be used as a dwelling, access must be from an alley or an approved driveway, and the accessory dwelling must be accessory to a single-family dwelling, Historic Bed and Breakfast, or Bed and Breakfast use.
Although accessory buildings generally may not occupy more than 30 percent of the required rear yard, an Accessory Dwelling Unit may cover more than 30 percent provided it is no more than 800 square feet (or the size of the primary dwelling, whichever is less) and meets the Design Standards defined elsewhere in the Ordinance. Permitted districts for an accessory dwelling are D-4, D-5, UN, MU-L, MU-M, MU-H, MU-D, C-1, and C-2.
Violations & Fines
Zoning violations are enforced by the Department of Planning, Engineering and Permits. A Zoning Violation Notice typically allows 14 working days to correct; uncorrected violations can lead to a summons to Environmental Court, where a Municipal Judge may fine the owner and/or order confinement in the Municipal Jail upon misdemeanor conviction.
Frequently Asked Questions
How big can an ADU be in Birmingham?
Which zoning districts allow an accessory dwelling in Birmingham?
Does Alabama have a statewide ADU law?
Sources & Official References
Other rules in Birmingham
How Birmingham compares: Easiest Cities to Build an ADU·Compare Birmingham to another location·View the Alabama accessory structures overview
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ADU Rules in Nearby Cities
How other cities in Jefferson County handle adu rules.